KR20100012447A - Construction system and method for concrete sunken well using a pontoon - Google Patents

Abstract

PURPOSE: A concrete well construction system using a buoyancy container and a construction method are provided to improve construction quality by minimizing underwater work without using large equipment and a large working area. CONSTITUTION: A concrete well construction method using a buoyancy container is as follows: Buoyancy containers are manufactured around a steel caisson and transferred to a sea or river(S10). A well is manufactured on the top of the steel caisson using a form(S20). A guide rail is installed on the outer surface of the well and flooded by being slid to the bottom of the buoyancy containers(S30). A new well is manufactured on the top of the existing well(S40). A new guide rail is installed on the outer surface of the new well and flooded by being slid to the bottom of the buoyancy containers (S50). It is determined whether the well is sufficiently constructed to a target support layer(S60).

Description

Construction System and Method For Concrete Sunken Well Using A Pontoon

The present invention relates to the construction system and construction method of the bridge foundation placed on the sea or river, and more specifically, by applying a buoyancy (Pontoon) to the construction work of the concrete well bucket to enable the water works large equipment and large work The present invention relates to a concrete well bucket construction system and a method using buoyant canisters that are improved in order to achieve economical construction and safe work.

In general, the foundation work of marine bridges such as year bridges and bridges, and bridges that cross rivers and reservoirs are subject to many restrictions in terms of constructability due to the specificity of the surrounding conditions, and the safety problems due to huge construction costs and underwater work should be preempted. There is difficulty.

Representative basic construction methods for bridges currently on the sea or in rivers can be called large-diameter RCD, stationary, and submerged wells, but these methods are designed to operate large equipment, use expensive raw materials, and danger of underwater work. Since it is inherent, it can be said that it is inadequate to satisfy both economic feasibility, constructability, and safety.

In Korean Patent Application Publication No. 10-0270978, "Waste box installation device and installation method for foundation work of piers", shortening the construction period by improving blasting efficiency by blasting work while preventing water from entering into the well. At the same time, it provides the technology to work safely.

Such a conventional well installation device for a pier foundation work includes a bracket attached at regular intervals to a lower inner circumference of a well used for an excavation work during a foundation work of a pier well, and a round bar or angle connected to the attached bracket. One or more piles are installed between the rod-shaped support and the bracket at a position corresponding to the bottom surface side of the well and the space portion side generated from the ground, and one surface is in contact with the other side of the upper portion of the pile. The side surface includes a wedge for contacting the well barrel tip and supporting the pile at an angle, and fixing members for preventing the pile from being separated by buoyancy of the water before the wedge is put.

In addition, Korean Utility Model Publication No. 20--232748, "Steel caisson for bridge foundation repair work," is presented. This conventional technique can prevent water pollution and enormous temporary barriers, and it is easy to install and dismantle steel caisson's temporary barriers by using buoyancy of water. Provide caisson.

In the conventional art, when repairing a well foundation formed at the lower portion of a bridge, the well foundation is integrally formed by coupling flanges of the lower end, the middle and the upper end caisson with flange joint bolts on the outside thereof. The steel caisson is installed, and the lower end, the middle and the upper end caisson are respectively coupled to the inner wall and outer wall iron plate so that water does not pass through the inner and outer. In addition, the inner wall iron plate and the outer wall iron plate is formed in the horizontal and oblique direction to maintain a constant frame and distance when combined, the upper caisson forms a working scaffold protruding outside the outer periphery of the upper end, on the base of the well Adjacent steel caissons are combined and dismantled using cranes installed on barges during installation and dismantling.

Meanwhile, a steel caisson is used as a water barrier to prevent water from flowing into the well base so as to allow dry concrete work on the broken water basin foundation by placing a water-blocking concrete on the inner water bottom of the well base and the steel caisson. It is a technique to use.

In addition, "Utility Model Registration Publication No. 20-0380084" of the caisson assembly for repairing underwater structures is presented. This prior art relates to caisson assemblies used in the repair of underwater structures, such as piers and well foundations, which are the foundations of bridges. Provided is an caisson assembly for repairing an underwater structure, through which a watertight rubber material is interposed between the outer surfaces of the structure, and fastened and assembled through a fastening member, thereby performing reliable repair of the underwater structure.

However, these conventional techniques are all the technology for the foundation construction of the bridge using the caisson, but most of them use heavy equipment such as large cranes, there is a problem that requires a large work space. In addition, since most of the work is made by underwater work, it is difficult to secure the construction quality stably, and there is a problem in that the construction cost is high and the safety of the work is lowered.

The present invention is to solve the conventional problems as described above, its purpose is to apply a buoyancy bucket (Pontoon) to the construction of concrete wells can be aquatic work, so large equipment and large working space is unnecessary, underwater work The present invention provides a concrete well construction system and construction method using buoyancy cans that can improve construction quality through minimization.

In another aspect, the present invention is possible to construct a concrete concrete pail by using a buoyancy pass through the guide rail, the organic buoyancy can be operated according to the scale of the well, thereby reducing the construction cost through economical construction, and made a safe operation The present invention provides a system and method for constructing concrete wells using buoyant canisters that have been improved to be built.

In order to achieve the above object, the present invention, in the bridge-based construction system placed on the sea or river,

Steel caisson;

A buoyancy bucket having a frame surrounding the caisson and having a plurality of floats mounted to the frame to provide buoyancy;

A well casing connected to the upper and lower coaxial stages at the upper portion of the caisson and gradually descending to the water along the guide rail with the caisson; And

A braking device mounted to the buoyancy cylinder to allow vertical movement of the caisson and the well cylinder with respect to the buoyancy cylinder or stopping in place by braking the guide rail; It provides a concrete well bucket construction system using a buoyancy bucket, characterized in that it is configured to be manufactured and installed in the water by stepping down into the water.

In addition, the present invention preferably the buoyancy cylinder is provided with a plurality of sub-floating bodies arranged to be detachable between the four main floating body and the main floating body disposed on all sides of the caisson buoyancy control of the buoyancy cylinder is It provides a concrete well construction system using a buoyancy bucket characterized in that possible.

And the present invention is preferably the guide rail is disposed on all sides of the caisson and the well, coupled to the braking device of the main floating body provided in the buoyancy cylinder is characterized in that for supporting the caisson and the well from all sides To provide concrete well construction system using buoyancy bucket.

In another aspect, the present invention preferably provides a concrete well construction system using a buoyancy bucket, characterized in that to support the buoyancy of the buoyancy bucket having a degree plate blocking the inside of the well bucket in the middle. .

And the present invention preferably provides a concrete well bucket construction system using a buoyancy bucket, characterized in that the order plate is provided with an opening and closing for underwater concrete pouring.

In another aspect, the present invention preferably is a braking device having a guide groove of the "⊥" type in which the guide rail is inserted, and a plurality of cylinder devices to grip the web (web) of the guide rail on both sides buoyancy Provide a concrete well bucket construction system using a bucket.

In order to achieve the above object, the present invention is a bridge-based construction method placed on the sea or river,

Making a buoyancy bucket around the steel caisson and launching it to sea or river;

Manufacturing a well using a formwork at the top of the caisson;

Installing a guide rail on the outside of the well, slid to the bottom of the buoyancy bucket submerged in water and braking;

Manufacturing a new well in the upper side of the well;

Installing a new guide rail on the outside of the new well and sliding it under the buoyancy bucket to submerge and brake underwater;

Determining whether the well is built up to the desired target support layer; including, constructing a concrete well using buoyancy buckets, which continuously constructs and gradually floods the new well to reach the desired target support layer. Provide a method.

And the present invention preferably is the step of manufacturing the new well bucket concrete using a buoyancy bucket, characterized in that to support the buoyancy of the buoyancy bucket, including the step of installing a degree plate blocking the inside of the well bucket in the middle Provide a well construction method.

In another aspect, the present invention preferably provides a concrete well construction method using a buoyancy bucket characterized in that the step of installing the degree plate in the middle is to adjust the buoyancy of the buoyancy bucket through the filling of water on the top of the order plate. do.

According to the present invention, by applying a buoyancy bucket (Pontoon) to the construction of concrete wells can be a water work, large equipment and large work space is unnecessary, it is possible to minimize the underwater work. In this way, the production and connection connection work of the well can be achieved in the water phase, so that the construction quality can be improved, and the effect of safe work is obtained.

In addition, according to the present invention, it is possible to construct a concrete well bucket for each step using a buoyancy passing guide rail, and to adjust the buoyancy of the buoyancy bucket as well as to operate the organic buoyancy bucket using the order plate in consideration of the size and depth of the well bucket. It is possible to avoid the inefficiency of the tube production and to reduce the construction cost through economical construction.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

The concrete well bucket construction system 1 using the buoyancy bucket according to the present invention is a bridge foundation construction system which is placed on the sea or on a river.

The concrete well bucket construction system 1 using the buoyancy bucket according to the present invention has a steel caisson 5 and a frame 12 surrounding it, as shown in FIG. 1, and is mounted on the frame 12. Buoyancy cylinder 10 is provided.

The caisson 5 is a cylindrical steel structure, and forms a lower portion of the bridge.

In addition, the buoyancy cylinder 10 disposed around the caisson 5 is provided with a plurality of floating bodies 15a and 15b to provide buoyancy. Such a buoyancy cylinder 10 is a frame 12 manufactured in a circular shape. A plurality of sub-floating bodies (4) arranged between four main floats (15a) arranged on all sides of the caisson (5) and detachably attached to the frame (12) between the main floats (15a) 15b).

Since the main floating body 15a and the sub floating body 15b have a hollow space therein, the buoyancy control of the buoyancy cylinder 10 is possible according to the size and number of the buoyancy cylinder 10. In addition, such buoyancy barrel 10 can be replaced quickly when the floating body is broken, easy to dismantle after use once, can be recycled after demolition.

And the present invention has a well 20 which is connected in stages in the upper and lower coaxial phase in the upper portion of the caisson (5). The well 20 is made of a cylindrical structure using concrete, as shown in Figure 1b, is connected to the upper side of the caisson 5, the guide rail 30 together with the caisson 5 It is a structure that descends into the water step by step.

Such a well 20 is connected to the buoyancy cylinder 10 through a guide rail 30, such a guide rail 30 is made of steel of the "H" type, caisson 5 and the well bucket Four are arranged in four directions in the up-and-down direction, and the caisson 5 and the well 20 are coupled to the braking device 40 of the main floating body 15a provided in the buoyancy cylinder 10. It is a structure supported from all directions.

That is, the guide rail 30 protrudes the concrete block 22 on the outer wall of the well 20 as shown in FIG. 2, and has a shape of “H” mounted through a plurality of fixing bolts 24. The guide rail 30 is made of steel, and as described later, each of the wells 20 to be newly manufactured is successively connected to the upper side thereof to form a long vertical rail structure.

In addition, the guide rail 30 is provided with a braking device 40 mounted to the buoyancy cylinder 10 for braking the guide rail 30, such a braking device 40 is shown in Figure 3a, b As shown in Fig. 2, the frame 12 is provided with a guide groove 42 of the “⊥” type into which the guide rail 30 is inserted, and the web 32 of the guide rail 30 is gripped from both sides. It is a structure provided with the some cylinder apparatus 35 to grapple. Such a cylinder device 35 is composed of a conventional hydraulic or pneumatic cylinder, and presses both sides of the web 32 of the guide rail 30 with hydraulic or pneumatic force, and then applies a brake force (not shown) ) Is provided on the cylinder rod 37. Thus, such a braking device 40 operates to allow the vertical movement of the caisson 5 and the well 20 to the buoyancy cylinder 10, or to stop in place.

Meanwhile, as shown in FIG. 4, the well 20 is provided with an order plate 50 blocking the inside of the well 20 in the middle thereof to assist buoyancy of the buoyancy cylinder 10. The order plate 50 blocks the inner diameter of the well 20 to block water from entering the upper side thereof. Therefore, the order plate 50 provides a buoyancy space to the upper side thereof, and as described later, when the water is filled in the buoyancy space, the buoyancy intensity is controlled. Such an order plate 50 is more effective once it is constructed is no need for a separate demolition work.

And the order plate 50, as shown in Figure 5a), b), has a structure having an opening and closing port 52 for placing concrete underwater in the middle. When the concrete is to be poured into the well 20, it is necessary to supply the underwater concrete to the lower side of the order plate 50, in this case, through the opening and closing port 52 to the concrete order plate 50 Concrete can be supplied to the lower side of the.

The concrete well bucket construction system 1 using the buoyancy bucket according to the present invention configured as described above continuously produces the well bucket 20 on the upper side of the caisson 5 and descends stepwise into the water well ( 20) will be installed continuously.

As shown in FIG. 6A, the concrete well bucket construction system 1 using the buoyancy bucket of the present invention has the upper side of the caisson 5 in a state where the caisson 5 is first connected to the buoyancy bucket 10. Install the formwork (29) on the concrete.

Then, after removing the formwork 29, the guide rail 30 is mounted on the outside of the manufactured well 20, in this case side by side to the upper side of the guide rail 30 already installed in the caisson (5). The guide rail 30 is arranged and fixed using the bolt 24.

Next, as shown in Figure 6c, when the braking device 40 provided in the buoyancy barrel 10 is released, the caisson 5 and the well 20 is submerged into the water by the weight (self-weight), the well When the lower end of the 20 is submerged in the water, the braking device 40 is operated to stop further inundation of the well 20, and fix the position thereof. In addition, a new formwork 29 is installed on the upper side of the well 20 submerged in this way, and the concrete is poured.

When the production and immersion of such a new well 20 is repeated a certain number of times, the well 20 of a certain depth is submerged under water. In this case, the buoyancy bucket (depending on the size and size of the well 20) 10) It is difficult to endure the load with only buoyancy. In this case, as shown in FIG. 7A, an order plate 50 is installed in the middle portion of the well 20 to block the inside of the well 20. The order plate 50 may compensate for the insufficient buoyancy of the buoyancy cylinder 10 by preventing the water from flowing into the upper side thereof to generate the buoyancy of the well tank 20 itself.

When the construction of the degree plate 50 is completed as described above, a new formwork 29 is installed next to the upper side of the degree plate 50, and an additional well 20 is made, as shown in FIG. 7B). In the same manner, the wells 20 are continuously extended to the upper side of the order plate 50.

Through this process, the caisson 5 constructs the well bucket 20 until the target ground P is reached, and as shown in FIGS. 7C and d), after reaching the target ground P, Dismantle the buoyancy tube 10, fill the water in the well 20 to stabilize the well 20, then construct the bridge foundation.

As described above, according to the present invention, the wells 20 are continuously manufactured at the upper side of the caisson 5, and are stepped down into the water to install the wells 20 in the water and the bridge foundation work can be performed.

Hereinafter, with reference to Fig. 8 with respect to the concrete well bucket construction method (S) using a buoyancy bucket according to the present invention will be described in more detail.

Concrete well construction method (S) using a buoyancy bucket according to the present invention is first made a step (S10) to launch a buoyancy bucket 10 around the steel caisson 5 to the sea or river.

For such a step (S10), first, in the manufacturing site of the land to prepare in advance the buoyancy barrel 10 and the steel caisson 5, the guide rail 30 and the frame 12. In this way, the buoyancy bucket 10 and steel caisson 5, guide rails 30 and the frame 12 produced in the on-shore manufacturing site are transported to the sea or river, and then to the target construction location using a barge, etc. Launched by sea or river after transfer.

Then, after launching in this way, it is settled to prevent the positional change, and then, a step S20 of manufacturing the well 20 using the formwork 29 at the upper portion of the caisson 5 is made. In the process of manufacturing the well 20 using the formwork 29, the construction quality of the formwork 29, concrete placing and disassembly of the formwork 29 are greatly increased by the construction of the caisson 5 on the land. It can be improved, and stable working conditions can be formed and can be easily worked.

Then, the guide rail 30 is installed on the outside of the well 20, and sliding down to the lower portion of the buoyancy tube 10 is submerged in water and braking (S30). In the step (S30) as described above is to make the well bucket 20 is completed, in this case, the braking device 40 is released and the immersion by the weight of the caisson (5) and the well bucket 20 is made (self-weight) After immersion, when the well 20 of the desired depth is immersed, the braking device 40 is operated to fix the well 20.

In addition, the next step (S40) of making a new well 20 in the upper side of the well 20 is made. In the manufacturing step (S40) of such a new well 20, the formwork 29 is continuously installed on the upper side of the already produced well 20, concrete is poured, and then the formwork 29 is dismantled. The well 20 will be manufactured.

Next, a new guide rail 30 is installed on the outside of the new well 20, and sliding to the lower portion of the buoyancy cylinder 10 is submerged in water and braked (S50). In such a step (S50), the wells 20, which have been newly manufactured, are lowered together with the wells 20 that have already been submerged. In this case, as in the above process, the braking device 40 is released and the caisson 5 is released. Then, the immersion by the weight of the well 20 is made, and when the immersion of the well 20 of the desired depth is made, the braking device 40 is operated to fix the well 20.

The process of manufacturing such a new well 20 and continuously immersed in steps is repeated a certain number of times, and then a step (S60) is performed to determine whether the well 20 is constructed up to a desired target support layer. In the determination step (S60) as described above, if the well tank 20 reaches the desired target support layer, the construction is completed. If not, the new well tank 20 is continuously manufactured and flooded in stages to achieve the target ground (P). Will extend the well 20 to the construction.

And in this process, the present invention further includes the step of installing the order plate 50 to block the inside of the well 20 during the step (S40) of manufacturing the new well 20 in the middle.

As such, the process of installing the order plate 50 in the middle of the bridge is large and large, so that it is difficult to support the load of the caissons 5 and the wells 20 only by the buoyancy cylinder 10 itself. 20) it is to assist in the buoyancy of the buoyancy tube 10 by allowing buoyancy to be generated in itself.

The process of installing the order plate 50 is as shown in Fig. 4a), b) on the well 20 at the lower portion of the position to install the order plate 50, as shown in FIG. Similarly, the work hole 55 for installing the order plate 50 is formed. Such work holes 55 are installed on all sides to facilitate the installation of the order plate 50, and install formwork (not shown) for installing the order plate 50 on the upper side of the work hole 55. Then, as shown in Figure 4c) to cast concrete to construct the order plate 50. After the construction of the order plate 50 is completed as described above, the formwork is dismantled, and as shown in FIG. 4D, the work hole 55 is poured by concrete and closed to complete the installation of the order plate 50.

Meanwhile, in the process of installing the order plate 50 in the middle, as shown in FIG. 5, the opening and closing port 52 for placing underwater concrete may be installed as shown in FIG. 5. When the installation of the order plate 50 is completed as described above, the buoyancy of the buoyancy tube 10 may be assisted by filling the upper portion of the order plate 50 with water. That is, the buoyancy of the well 20 can be adjusted by filling water in the upper portion of the order plate 50, and the buoyancy of the well 20 is the strength of the buoyancy that the buoyancy 10 must bear as a whole. As a result, the buoyancy of the buoyancy barrel 10 is subsidized.

As described above, the present invention is possible by applying a buoyancy bucket (Pontoon) (10) to the construction work of the concrete well bucket 20 for the foundation work of the bridge to enable the water works, large equipment and large working space is unnecessary, underwater work Minimization of can be achieved. Therefore, the production and connection connection work of the well 20 is made in the water can achieve the improvement of construction quality, the work is made safely.

In addition, it is possible to construct the concrete well trough 20 in the water phase, and adjust the buoyancy of the buoyancy canister 10 through the sub-floating body (15b), as well as considering the size and depth of the well trough 20 (order plate ( Operation of the organic buoyancy bucket 10 using 50) can achieve the work efficiently, and it is possible to reduce the construction cost through economical construction.

Although the present invention has been described in detail with reference to the accompanying drawings, the present invention is not limited to such a specific structure. Those skilled in the art will be able to variously modify or change the embodiments of the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. Nevertheless, it will be apparent that all such modifications or design modifications to such simple embodiments will clearly fall within the scope of the present invention.

1 is a view showing a concrete well bucket construction system using a buoyancy bucket according to the present invention, a) is a plan view, b) is a sectional view;

Figure 2 is a view showing a guide rail provided in the concrete well construction system using a buoyancy bucket according to the present invention,

a) turning flat section, b) turning positive section, c) turning side section;

3 is a view showing a guide rail and a braking device provided in a concrete well bucket construction system using a buoyancy bucket according to the present invention,

a) a drawing flat section, b) a drawing side section, c) a drawing enlarged section;

4 is a construction flowchart of the order plate provided in the concrete well bucket construction system using a buoyancy bucket according to the present invention,

a) turning flat section, b) turning side section,

c) the side section in which the turning order plate is installed,

d) the side cross-section in which the turning order plate installation is completed;

5 is a view showing the opening and closing port of the order plate shown in FIG.

a) turning flat section, b) turning side section;

6 is a view showing the concrete construction method construction method step by step using a buoyancy bucket according to the present invention,

a) section where the well tub was constructed at the upper part of the turning caisson,

b) Sectional view where the guide rail is installed in the well of the upper caisson

c) a section in which a die is installed in the well tub of the upper part of the caisson;

7 is a view showing step by step construction method of concrete well bucket using buoyancy bucket according to the present invention,

a) section, which constructed the degree plate on the turning well tub,

b) the cross-sectional view of buoyancy control by filling the upper part of the degree plate,

c) section for constructing a well bucket to the turning target ground;

d) cross-sectional view of demolition of buoyancy pails and water filling in wells;

8 is a flow chart showing the concrete construction method construction method step by step using a buoyancy bucket according to the present invention.

<Description of Symbols for Major Parts of Drawings>

1 ..... Concrete well construction system using buoyancy bucket

5 ..... steel caisson 10 ..... buoyancy bucket

12 .... Frame 15a, 15b .... Float

20 .... wells 22 .... concrete blocks

24 .... Fixing bolt 29 .... Formwork

30 .... guide rail 32 .... web

35 .... Cylinder system 40 .... Braking system

37 .... cylinder rod 42 .... guide groove

50 .... order plate 52 .... switchgear

S ..... Construction method of concrete well using buoyancy bucket

S10 ... step of making a buoyancy bucket and launching it to sea or river

S20 ... steps to build a well at the top of the caisson

S30 ... submerging and braking the well to the bottom of the buoyancy pail

S40 ... step of making a new well at the top of the well

S50 ... submerging and braking the new well into the lower part of the buoyancy bucket

S60. Step of determining whether the well is built up to the target support layer

Claims (9)

In a bridge-based construction system placed on the sea or river, Steel caisson A buoyancy bucket having a frame surrounding the caisson and having a plurality of floats mounted to the frame to provide buoyancy; A well casing connected to the upper and lower coaxial stages at the upper portion of the caisson and gradually descending to the water along the guide rail with the caisson; And A braking device mounted to the buoyancy cylinder to allow vertical movement of the caisson and the well cylinder with respect to the buoyancy cylinder or stopping in place by braking the guide rail; Concrete well bucket construction system using a buoyancy bucket, characterized in that it is configured to be installed in the water by stepping down into the water step by step. According to claim 1, The buoyancy cylinder is provided with a plurality of sub-floating bodies arranged to be detachable between the four main floating body and the main floating body arranged on all sides of the caisson is capable of adjusting the buoyancy of the buoyancy cylinder Concrete well construction system using a buoyancy bucket, characterized in that. According to claim 1, The guide rail is disposed on all sides of the caisson and the well, buoyancy, characterized in that to support the caisson and the well from all sides by coupling to the braking device of the main floating body provided in the buoyancy cylinder Concrete well construction system using barrels. According to claim 1, wherein the well is a concrete well construction system using a buoyancy bucket, characterized in that to support the buoyancy of the buoyancy bucket having a degree plate in the middle to block the inside of the well. The system of claim 4, wherein the order plate is provided with an opening and closing hole for placing concrete under water. The buoyancy cylinder according to claim 1, wherein the braking device has a guide groove of a "⊥" type in which the guide rail is inserted, and has a plurality of cylinder devices that grip the web of the guide rail from both sides. Concrete well construction system In the construction method of the bridge foundation put on the sea or the river, Making a buoyancy bucket around the steel caisson and launching it to sea or river; Manufacturing a well using a formwork at the top of the caisson; Installing a guide rail on the outside of the well, slid to the bottom of the buoyancy bucket submerged in water and braking; Manufacturing a new well in the upper side of the well; Installing a new guide rail on the outside of the new well and sliding it under the buoyancy bucket to submerge and brake underwater; And Determining whether the well is built up to the desired target support layer; including, constructing a concrete well using buoyancy buckets, which continuously constructs and gradually floods the new well to reach the desired target support layer. Method. The concrete well using a buoyancy bucket according to claim 7, wherein the manufacturing of the new well bucket includes assisting the buoyancy of the buoyancy bucket, including installing a middle plate blocking the inside of the well bucket. Bucket construction method. 9. The method of claim 8, wherein the step of installing the order plate in the middle is to adjust the buoyancy of the buoyancy cylinder by filling the upper portion of the order plate with water.

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